Many varieties of palm trees (for example, washingtonia, filifera and robusta) have an appearance which is very much improved by periodic maintenance which includes skinning the trunk and peeling away the lowermost fronds. It is characteristic of the growth pattern of palm trees that the lower fronds tend to die and droop in a most unsightly manner as a tree extends its frond cluster upwardly with new growth. As a result, the typical maintenance of a palm tree involves climbing the tree and cutting the expired individual fronds near their points of attachment to the tree trunk. For some varieties, such "stubs" as may have been left by a prior trimming tend to become sufficiently weakend over a period of time (at least in some palm tree varieties) that they can be peeled away from the trunk to leave a very attractive "skinned" appearance, and a skinning operation is therefore often carried out at the same time as the trimming operation.
In order to maintain the desired appearance, palm trees have to be maintained in the manner noted above at least once a year and, for some varieties, more often than annually. The procedure involves either the use of long ladders or climbing the tree using traditional poleman's climbing spikes to reach a position at which the trimming (and/or skinning) operations are to take place. At that position, the workman passes a safety belt around the trunk of the tree and undertakes the trimming operation typically using a chain saw. The skinning is done by hand, sometimes following a supplementary cutting operation if a given stub is not quite peelable.
The time consuming, expensive and sometimes dangerous aspects of this traditional procedure are notoriously well-known to those skilled in the art. Not only are the ascent and descent steps potentially dangerous, but the use of a chain saw under the necessarily restricted conditions is manifestly an area for caution and concern. A still further potential source of danger is found in an occasional encounter with poisonous insects, such as scorpions and black widow spiders, which are native to many areas in which palm trees flourish.
It is toward eliminating these dangers associated with maintaining palm trees, as well as performing such operations in a simpler and less time consuming manner, that my invention is directed. Briefly, my invention contemplates apparatus which may be engaged with the trunk of a palm tree near ground level and which will thereafter ascend, on its own motion, skinning and trimming the tree as it progresses. Once the skinning and trimming operations have been carried out, the apparatus descends the trunk for ready removal and transfer to another tree.
Apparatus adapted to "climb" the trunks of deciduous trees and clear branches therefrom as it ascends is contemplated in the prior art although it will be understood by those skilled in the art that this task is a substantially different problem from that addressed by the present invention. Representative of such apparatus are implements disclosed in U.S. Pat. Nos. 4,279,281 to Nakamura; 3,461,925 to Fend; 3,457,973 to Meier; 3,454,058 to Fend; 3,385,332 to Otterbach et al; 3,364,962 to Otterbach et al; 3,364,961 to Otterbach et al; and 3,315,714 to Meier. These prior art references share common drawbacks. They are heavy, bulky and complex, with most of the devices disclosed literally carrying chain saws aloft to effect the debranching operation. Each is also characterized by the incorporation of driving means which must be skewed upwardly to force the apparatus to climb the trunk. My invention, which is specifically directed to the maintenance of palm trees, does not share these multiple drawbacks of complexity, weight, expense of construction, difficulty in use, etc. which are clearly present in these prior art devices for delimbing and trimming deciduous trees.